Briefly: "Squaw" is an Algonquian term for "woman" that "has been considered offensive since the late 20th century if not earlier." In the past decade, the term has been deemed too unseemly to grace the world's peaks, waterways, even species of ducks. Now, only novelty lace-up 15-percent-spandex mini-dresses carry on the linguistic tradition.

"Squaw" is likely not derived from a slang term for genitalia, as some have reported (though the "Seductive Squaw" costume's tenuous fringe crotch covering may change that!) But as Cecil Adams wrote in 2000:

One doesn't want to get overly PC about it, but the protesters have a point when they say special terms for minority women are inherently demeaning. Think about it. Negress. Jewess. Sixty years ago these terms were in common use. Now they make your flesh creep. Next picture some pot-bellied slob in a cowboy hat: "Why, if it ain't a injun and his squaw." In 1967, 143 place names containing the word nigger were changed to Negro by order of the U.S. Board on Geographic Names. Squaw Valley may not be in the same league as Nigger Lake on the offensiveness scale. But it's up there with Pickaninny Creek.

Take a "squaw" and dress her up in a gross approximation of native dress—gold bangles, pink headband, moccasin legwarmers? Sure—and you've got 2010's most racist costume yet.